Bed block will worsen at Wollongong Hospital if the controversial $7 Medicare co-payment comes into play, according to a representative of the nurses' union.

Anne Frew, the Wollongong Hospital branch president of the NSW Nurses and Midwives Association (NSWNMA), said the federal government proposal would lead to patients flooding emergency wards.

"It will mean people will bypass their GPs and instead head to the emergency department for conditions their GPs could have attended to," she said.

"This will crowd our emergency department and block up our beds - and we're already under stress with bed block in Wollongong.

"Unlike Sydney hospitals, which can refer patients to other major metropolitan hospitals if their EDs are full, we are the major referral centre for the Illawarra health district and have to accept every patient who comes through the door."

Nurses and midwives held a short rally on Tuesday afternoon in opposition to the changes, which will begin in July next year if passed by the Senate.

NSWNMA regional organiser Mark Murphy said members held the rally to urge the government to rethink the proposal.

"We know the new Senate is meeting in Canberra this week to make decisions, and the Medicare co-payment is one of the big items on the agenda," he said. "In light of that we're here to highlight the dangers of a co-payment being introduced."

Nurses held placards and banners urging the government to keep its "hands off Medicare" and not to copy the US healthcare system.

"We currently have a universal healthcare system that's fair and equitable, and which we already pay a levy for," Mr Murphy said.

"A co-payment on top of that would see us heading down the path of the American healthcare system - a two-tiered system where those who can afford it get access to healthcare, and those who can't afford it don't.

"We know that people are being bankrupted because they can't afford healthcare in the US, and in the worst cases people are dying because they can't get care."